Electric heater



Feb. 26 1924.

F. E. WOLCOTT ELECTRIC HEATER Filed may 19. 1921 iii.

/ VENTOR Patented Feb. 26, 1924.

UNITED. STATES PATENT OFFICE.

ram r. WOLCOTT, or nan'rronn, comorrco'r.

ELECTRIC HEATER.

Application and m 19, 1921. Serial No. 470,852.

Toallwhom it may concern; a

Be it known that I, FRANK E. \Vonoorr, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Electric Heatersfof'which the following is a specification.

This invention relates to electric heating devices and has particular reference to electric grids or the like.

Among the objects of the invention is to provide an electric heating device having a number of peculiarly advantageous features of construction and operation, among which may be suggested the following: (1) Simplicity of construction; (2) reliability and convenience of o eration, as well as durability of service; 3) neatness of appearance and compactness of design,'and many other advantages that will be apparent to those skilled in the art or who may have experience with the use of the improvement.

With the foregoing and other objectsin view the invention consists in the arrangement and combination of parts'hereinafter described and claimed, and-while the invention is not-restricted to the exact details of construction" disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which- Figure 1 is a. plan view of one form of my improvement.

Fig. 2'is a vertical transverse section of the. same on the line 2-2. I

Referring now more specifically to the drawings, I showmy improvement as comprising a heating unit of peculiar construction and design, and a suggestion of a grid interchangeably associated with the heating unit.

The heating unit comprises a casing 10 of any suitable refractory material such as sheet metal, the main structural feature of which isindicated as a symmetrical cone, surrounding which is a substantially flat rim or base 11, from the periphery of which.

projects downward a skirt or flange 12 of circular form, as'shown. ,This flange lends rigidity of strength to the device and constitutes a means forattaching any suitable form of feet or legs 13. These legs may be of any suitable material or design, and I have successfully used for this purpose rectangular blocks of fiber each having a slit formed in its upper end to receive the flange 12. These-parts may be fastened together either frictionally or by some positive means such as a rivet-14 passing radially therethrough. The apex of'the conical casing 10 is 1slightly flattened and is provided with a Fitted within the cone 10 and formed as a counterpart thereof is a heating unit body 15 made of any suitable insulating material such as porcelain or its equivalent, the same carrying embedded or otherwise secured therein or thereto a resistance member 16 such as a coil of wire extending spirally around or along practically all of the comcal up 1' surface of the body. The formation 0 the body as shown afi'ords great sur-,

face capacity for the resistance member in relation to the horizontal expanse thereof, and this great heating efliciency is afforded even though the device as a whole may -occupy a relatively small amount of space; The bottom of the body 15 is cambered. or upwardly-recessed as shown at 17 forming a dead air space, and the axis of the body is formed with a hole registering" with the hole in the apex of the casing.

Beneath the body is a canopy 18 comprising a main flat portion and an upstandmg peripheral flange 19 which embraces the periphery of the body15 and makes contact with'the casing at about the line of con-v nection between the conical and flat portions thereof. Supported within the canopy and beneath the dead air space 17 is a heat insulating member 20 indicated. as in the form of a disk of asbestos or its equivalent. This heat insulating member is substantially co-extensive with the. flat portion of the canopy. A fastening member .such as a bolt passes axially downward through the apex of the casing, the body 15, and the centers of the disk and canopy, serving to lock or fasfire therefrom by reason of the air space and protection beneath it.

The grid 22;,as shown comprises a rigid member of any suitable size, design, or me.-

terial, depending upon the purpose for w ich it is to'be used. As indicated it has a flat circular top and a depending solid body 23 having a central recess or cavity formed as a counterpart of the conical casing 10 with which it is adapted to directly co-operate in practice. By reason of this construction of the grid it may be placed readily upon the heating unit and so be self centering and hence self leveling, a matter of special importance not only for heating purposes but also for the baking of cakes or the like from soft batter. Moreover, the design of these cooperating parts lends itself to the easy interchange of various types of grids or other receivers for use successively on the same heating unit. lVith the grid made with a heavy solid body, it not only is well adapted for holding and discharging uniform heat but also is best adapted for holding itself in position upon the casing. vVhile I have indicated the heat receiving member in the form of a grid it is to be understood that the spirit of the invention contemplates the provision of any suitable number, construction, or design of devices or utensils adapted for cooking purposes or for containing or supporting other bodies to be heatd, and irrespective of whether the bottom portion thereof for interchangeable co-operation with the heating unit is made solid or hollow. For instance, the heating unit is directly adapted for use as a base or support for a percolator whose body or bottom is hollow but provided with a cavity which as described is the counter part or the heating unit, and when removed from the base or heating unit will stand on its own bottom the same as any other percolator.

I claim:

1. In a heating device, the combination with a heat receiving member having a flat radiating surface, of a heating unit co-operating therewith, said member and unit being provided one with a tapered cavity on the side remote from the fiat surface and the other being correspondingly tapered to mate therewith to hold them automatically by direct surface contact in predetermined position with said flat surface horizontal.

2. A device as set forth in claim 1 in which the heating unit is provided with a projec tion extending upward into a similarly formed cavity in the heat receiving member.

'3. A device as set forth in claim 1 in which the heating unit comprises an upwardly projectin centering point having a smooth 'surroun ing contact surface.

4. A device as set forth in claim 1 in which the heating unit includes an upwardly projecting symmetrical cone constituting the counterpart of a recess formed in c bottom of the heat receiving member.

5. The herein described electrlo heating its bottom forming a dead air space, and

means is provided to close said space.

2'. A device as set forth in claim 5 in which the body is of insulating material and provided in its bottom with a recess forming an air space, and there is provided means to close said air space including heat insulating material.

8. The herein described electric heating unit comprising a casing having an upward conical projection and a heating body therein for the delivery of heat and for cooperation with a similarly formed heat'receiving member, said projection serving by direct surface contact to automatically center and retain said member.

9. In a device of the character set forth, a heat receiving member having a supporting body provided with a fiat disk shaped top surface and an upwardly directed cavity in its bottom surface so as to be self centering and self leveling in co-operation with a heat originating device having direct surface contact with the body.

10. A device as set forth in claim 9 in which the heat receiving member comprises a grid having a fiat top with a downwardly projecting body having a central upwardly projecting cavity therein.

11. The herein described electric heating unit comprising a conical casing of sheet material, a body of insulation of similar form fitted within the casing, a canopy of sheet material embracing the body, and means to lock the casing and canopy in fixed relation to each other.

12. A device as set forth in claim 11 in which the body and canopy are so formed as to provide a dead alr space between them.

13. A device as set forth in claim 11 in which the body is provided with an upwardly projecting conical cavity forming a dead air space.

14. A device as set forth in claim 11 in which the canopy has a flat central body portion and an upstanding peripheral flange making contact with the casing.

In testimony whereof I afilx my signature.

FRANK E. WOLCOTT. 

